Whooping cough, or pertussis, is surging across the United States, with major outbreaks reported in Texas, Florida, California, Oregon and several other states. Health officials attribute the rise to falling vaccination rates, waning immunity, delays in surveillance data and widening immunity gaps created during the pandemic years. Infants too young to be fully vaccinated remain the most vulnerable, prompting renewed warnings from clinicians and public health agencies.
Why Cases Are Rising Nationwide
Pertussis historically followed cyclical patterns driven by fading immunity, but the current spike is notable for its reach and scale. Nationally, more than 6,600 cases were reported in the first quarter of 2025, four times the pace of the previous year and far above 2023 levels. Multiple states are experiencing their highest case counts in a decade.
Lower vaccination uptake is a significant factor. Coverage for the childhood DTaP series declined after the pandemic, a trend worsened by rising nonmedical exemptions. Policy changes in Texas that allow parents to download exemption forms directly have further complicated tracking and enforcement. Dallas County officials report steep drops in back-to-school vaccinations and note that concerns over immigration enforcement may be discouraging some families from accessing care.
Another challenge is waning immunity. The United States shifted from whole-cell to acellular vaccines in the 1990s to reduce side effects, but the newer version does not protect as long. Many adults vaccinated with acellular shots as children have lost immunity, potentially transmitting the infection to infants without realizing it.
Impact on Infants and Young Children
Infants under one year face the highest risk of severe pertussis. Some stop breathing during coughing fits, and many require hospitalization. Pneumonia develops in about one in five hospitalized infants, and mortality remains a concern. To protect newborns, the CDC recommends a Tdap booster during every pregnancy so antibodies can pass to the baby before birth.
The once-promoted strategy of “cocooning” by vaccinating all caregivers has proven difficult to implement consistently and is no longer emphasized. Instead, timely maternal vaccination and starting the infant vaccine series at two months remain the strongest lines of defense.
Better Testing Reveals More Cases
Modern PCR panels, now common in clinics, detect pertussis more consistently than older methods and are uncovering infections that previously went undiagnosed. While improved detection explains part of the increase, the volume of infant hospitalizations and widespread state outbreaks show that true transmission has significantly expanded.
Emerging Concern Over Antibiotic Resistance
Pertussis is typically treated with macrolide antibiotics. Resistance to these drugs has become common in several countries, raising concern that resistant strains could spread through global travel. While resistant cases remain rare in the United States, health officials are monitoring the situation closely because treatment options for infants are limited.
Public Health Response and Next Steps
Experts stress that no single factor is responsible for the resurgence. Declining vaccine coverage, reduced maternal Tdap uptake, shrinking public health resources, immunity gaps and better detection all play a role. Several states have issued advisories urging clinicians to consider pertussis more readily, especially when treating infants or caregivers with prolonged cough.
Local health departments are working to rebuild programs scaled back after COVID funding ended, though limited staffing and slower immunization registry updates continue to create challenges. Obstetricians are encouraged to discuss Tdap during every pregnancy, while primary care providers are urged to check booster status for teens and adults.
Protecting Newborns During the Season
As respiratory infections peak during holiday gatherings, families with young infants are advised to take additional precautions. Ensuring that children and adults are up to date on vaccines for pertussis, influenza, COVID and RSV is critical. Sick visitors should stay away, and any infant with a cough, difficulty breathing or episodes of turning blue should receive immediate medical care.